Congenital Heart Disease

1357824 - Evaluation of lung maturation and pathological changes in fetuses with congenital heart disease by T2 mapping: comparison with fetuses without congenital heart disease

Wednesday, January 25, 2023

Location: E-POSTER

Presenting Author(s)

Keisuke Sato, MD

Head Physician
Shizuoka Children's Hospital
Shizuoka City, Shizuoka, Japan

Primary Author(s)

Keisuke Sato, MD

Head Physician
Shizuoka Children's Hospital
Shizuoka City, Shizuoka, Japan

Co-Author(s)

KS

Kazuya Sanada, MD

Head physician
Shizuoka Children's Hospital
Shizuoka City, Japan
YC

Yuhao Chen, MD

Pediatric CMR Trainee
Shizuoka Children's Hospital, Taiwan (Republic of China)
KS

Kyouhei Sano, RT

Radiologist
Shizuoka Children's Hospital, Japan

Background: Congenital heart disease sometimes alters the fetal lungs, such as "nutmeg lung" in severe cases of hypoplastic left heart syndrome (HLHS) or total anomalous pulmonary venous return (TAPVC). For such cases, qualitative evaluation by T2-weighted imaging is a standard method for evaluating the pathological changes in the fetal lungs. Recently, it has become possible to quantify the T2 value of the myocardium with T2 mapping. Here, we hypothesized that T2 mapping could be applied to quantitatively evaluate maturation and pathological changes in the fetal lung with congenital heart disease. Therefore, the objectives of this study were 1) to obtain T2 values in fetuses without pulmonary disease and 2) to compare T2 values in fetuses with pulmonary disease or congenital heart disease with those in fetuses without pulmonary disease.

Methods: T2 mapping was performed on 26 fetuses at Shizuoka Children’s Hospital between June 2021 and August 2022. All CMR examinations were performed with Ingenia 1.5T (Philips) and analyzed with cvi42 (Circle). The cross-section for T2 mapping was a coronal or transverse section of the fetus. The fetuses who underwent T2 mapping were divided into two groups: A) those without pulmonary disease and B) those with pulmonary disease or congenital heart disease, and T2 values were compared between the two groups. Information on the clinical course of the fetuses was obtained from the medical records or interviews with the attending physicians.

Results: There were 17 fetuses in group A and 9 in group B. Of the 17 fetuses in group A, 15 were born, 1 was aborted and 1 will be born shortly. T2 values in group A showed linear regression, although the approximate straight line differed depending on the weeks of gestation (GW): a gradual increase until about 28 weeks (163ms to 172ms, R²=0.59), a rapid increase from about 28 weeks to 35 weeks (172ms to 264ms, R²=0.67), and a decrease after 35 weeks (264ms to 139ms, R²=0.87). The diagnoses of the 9 patients in group B were HLHS+TAPVC in 1, variant HLHS+congenital pulmonary airway malformation (CPAM) in 1, congenital diaphragmatic hernia (CDH) in 4, CPAM in 1, trisomy 22 in 1, and thanatophoric dysplasia in 1. Seven were born, but two (vHLHS+CPAM, thanatophoric dysplasia) died. And, 1 died in utero (trisomy 22) and 1 will be born shortly (CPAM). The vHLHS+TAPVC case and the vHLHS+CPAM case had lower T2 values (170ms and 146ms, respectively) relative to weeks (222±17ms). T2 values for other diseases were low in CDH cases, high in a CPAM case, and extremely low in trisomy 22 and thanatophoric dysplasia cases.

Conclusion:

Fetal T2 values varied with the week of gestation, reflecting the process of lung maturation. T2 values were higher or lower in fetuses with congenital heart disease or pulmonary disease than in fetuses without pulmonary disease, and the application of T2 mapping to pulmonary assessment in fetuses with congenital heart disease may provide insight into postnatal lung status.